It is known for an actuator assembly to have an electric motor disposed within a housing. In such an arrangement, a space may be formed radially between the housing and the electric motor. This space may be filled with air, which is known to act as a good thermal insulator when confined. Heat may be generated by the electric motor during operation of the actuator assembly. If the heat generated by the electric motor is not able to be dissipated, excessive temperatures within the actuator assembly may result which may lead to unsatisfactory performance. In order to dissipate heat generated by the electric motor, it may be desirable to transfer heat to the housing which may be a good thermal conductor, for example, metal. Heat from the housing may then be transferred to the atmosphere and/or to a liquid coolant. However, the radial space between the electric motor and the housing may prevent an efficient transfer of heat from the electric motor to the housing. If a material with an ability to transfer heat more readily from the electric motor to the housing than air is used to fill the radial space between the electric motor and the housing, care must be taken to prevent the material from reaching the rotating components of the electric motor.
What is needed is an actuator assembly which minimizes or eliminates one or more of the shortcomings as set forth above.